Stage 1 of 8 · Tour du Mont Blanc

Chamonix-Mont-Blanc → Bionnay

Distance
21.1 km
Ascent
+1,151 m
Descent
-2,029 m
Est. Time
7h 49m
Altitude
975.7–2,468.5 m
Type
point-to-point
🏔️ Mountainous❄️ Alpine
🚌

Getting Here

Brevent (bus stop)

1842m from trailhead · ~23 min walk

🚌

Getting Out

Bionnay (bus stop)

787m from trail end · ~10 min walk

📥 Download GPX 🗺️ Open in Planner 🏔️ 3D Flyover 21.1 km · 1,151m gain

Elevation Profile

1,000m1,200m1,400m1,600m1,800m2,000m2,200m2,400m2,600m0 km5 km10 km15 km20 km21 km2,469m976m
Easy (5–10%) Steep (15–25%) Flat (<5%) Moderate (10–15%)

Route Map

🗺️ Open in Planner → | 🏔️ View 3D Flyover →

Segment Breakdown

Auto-analyzed from the elevation profile. Each segment shows the dominant character for planning your effort.

SegmentDist↑ / ↓TimeCharacter
Chamonix-Mont-Blanc → km 2.2 (2469m)
2,074–2,469m
2.2 km+442m / -48m1h 12m🔺 Steep Climb
km 2.2 (2469m) → km 16.3 (1674m)
976–2,469m
14.1 km+770m / -1565m4h 53m📉 Descending
km 16.3 (1674m) → Bionnay
1,198–1,674m
4.8 km+89m / -565m1h 22m🔻 Steep Descent
Total21.1 km+1,151m / -2,029m7h 28m

Pace & Fuel Calculator

Adjust your flat 10K pace to see personalized finish time, calorie burn, and hydration needs.

7:00 /km
4:00 /km (elite) 12:00 /km (leisure)
Fast Hiker / Jogger
Est. Finish Time
4h 42m
Calories
3,822 kcal
Water Needed
3.9 L
Effort Distance
42.8 km
flat-equivalent
🍫 Recommended: ~45g carbs/hr (212g total) 🧂 Electrolytes: ~2351mg sodium/hr 🩹 Consider anti-chafe and blister prevention

Terrain Analysis

Runnability
0%
Steep / Technical
% of route below 15% gradient
Climb Ratio
55 m/km
Steep profile
↑ 1,151m ↓ 2,029m

Surface & Technicality

Terrain Difficulty Breakdown
Runnable Flat (15%) Easy Grade (15%) Moderate Climb (26%) Steep (45%)

⛰️ Highly technical route. Power-hiking the steep sections is expected.

Current Conditions

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Conditions for June

ℹ️ Shoulder season
Snow Risk
0%
Unlikely
Mud Risk
30%
Moderate
Ice Risk
0%
Unlikely

✅ Snow unlikely at this elevation in June. Trail conditions expected to be clear.

🥾 Muddy sections likely. Waterproof boots recommended.

Best months: 5, 6, 7, 8, 9, 10

Suggested Gear List

Auto-generated based on 21.1 km, 1151m ascent, max altitude 2468.5m, ~8h duration.

Essential 8 items
  • 👟
    Trail running shoes / hiking boots
    Required for any trail
  • 📱
    Phone (charged) + offline map
    Navigation & emergency contact
  • 💧
    3L hydration vest
    No water sources on route
  • 🍫
    Trail mix, bars & sandwich
    Est. 4549 kcal burn
  • 🧴
    Sunscreen SPF 50+
    UV intensifies above 2000m
  • 🧢
    Sun hat / cap
    Exposed alpine terrain
  • 🧥
    Windbreaker / shell jacket
    Summit at 2468.5m — wind chill
  • 🆘
    Emergency space blanket
    Critical for preventing hypothermia if you stop moving
Recommended 6 items
  • 🕶️
    Sunglasses (cat 3+)
    Snow & rock glare at altitude
  • 🧤
    Warm mid-layer (fleece)
    Temps drop ~6°C per 1000m
  • 🔦
    Headlamp
    8h route — plan for delays
  • 🩹
    Mini first aid kit
    Blister plasters, tape, antiseptic
  • 🥢
    Trekking poles
    45% steep terrain, 1151m+ ascent
  • 🧊
    Microspikes / light crampons
    Snow risk in 12, 1, 2
Nice to have 1 items
  • 🦵
    Gaiters
    Keep snow out of boots

Logistics

This route runs from Chamonix-Mont-Blanc to Bionnay (21.1 km by trail). You'll need to arrange transport back to your starting point.

Start — Getting There
Chamonix-Mont-Blanc
🚌 Brevent (1.8km)
Finish — Getting Back
Bionnay
🚌 Bionnay (787m)
🗺️ Transit directions (Google)

Next Stage

Tour du Mont Blanc Stage 2: Bionnay → Le Barattet

→
← Back to all 8 stages of Tour du Mont Blanc

Take this route with you

Download the GPX file for your GPS watch or phone. Works with Garmin, Suunto, COROS, Apple Watch, and all GPX-compatible apps.

📥 Download GPX 🗺️ Planner

Route data from OpenStreetMap © contributors, licensed under ODbL. Updated 2026-04-03.